BX310x: Receive Notification from Server

How can I setup the BX310x to receive notification from a server?

I tried to send the descriptor value of "\00\01” with +SRBLEWRITEDESC.

With the Android App “BLE Scanner” I receive the notification from the server (which is also a BX310x).

The firmware revision is R1.3.0.201816011422.BX310x_1 on both devices (server and client).

What do I miss?

Thanks in advanced